int redLED = 9;       // Pin for the red LED
int greenLED = 10;    // Pin for the green LED
int buttonPin = 2;    // Pin for the button

void setup() {
  pinMode(redLED, OUTPUT);        // Set red LED pin as OUTPUT
  pinMode(greenLED, OUTPUT);      // Set green LED pin as OUTPUT
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as INPUT with internal pull-up resistor
  digitalWrite(redLED, HIGH);     // Turn on the red LED initially
  digitalWrite(greenLED, LOW);    // Ensure green LED is off initially
}

void loop() {
  if (digitalRead(buttonPin) == LOW) { // Check if button is pressed (LOW due to pull-up resistor)
    digitalWrite(redLED, LOW);         // Turn off the red LED
    digitalWrite(greenLED, HIGH);      // Turn on the green LED
   delay(3000);
        digitalWrite(greenLED, LOW);       // Turn off the green LED
   digitalWrite(redLED, HIGH);  
     delay(3000);      // Turn the red LED back on
    }                     
  
    }